Give Dominic O'Brien 54 packs of shuffled playing cards, show them the order once, and he can recite the sequence back to you in order, all 2808 cards. Most of us would just like to be able to remember where we put the car keys. O'Brien has won the World Memory Championships 8 times. He says having a good memory is not something you are born with, it's something you have to work at. He's written more than a dozen books about his memory development methods.